Review: Grand Seiko Spring Drive

Grand Seiko has mastered the art of both mechanical and electronic watchmaking, engineering Seiko Prospex Watches in both mechanical and quartz categories. That’s why the creation of Spring Drive is groundbreaking. Their command of both electronic and mechanical watchmaking is what allowed them to combine the two methods forge The Grand Seiko Spring Drive.

The Grand Seiko Spring Drive is a highly sophisticated and unique technology that sets it apart from other luxury watches. Though it generates energy much like other high-end watches, it stands out by combining mechanical technology with an electronic regulator that delivers a level of precision no other mechanical watch can compete with.

We know that watches with battery-powered quartz movement are typically mass produced and inexpensive. Grand Seiko incorporating quartz movement into their mechanical tech for the Spring Drive caught luxury watch enthusiasts off guard and has them asking, “why?”

The precision and reliability of quartz movement is more accurate than mechanical movement. The battery of a normal quartz watch emits a charge that results in an accuracy of 15 seconds +/- every 30 days. This allows deviation in precision by 15 seconds faster or 15 seconds slower a month. With Grand Seiko incorporating quartz movement to create the Spring Drive, the frequency rate of the quartz movement allows the second hand to move smoothly.

Spring Drive is the most accurate watch on the market now.

Grand Seiko Spring Drive combined the ingenuity of traditional mechanical watch engineering with the accuracy of quartz movement to produce an accuracy of 1 second +/-. It’s more precise than METAS certified Master Chronometer and COSC certified Chronometer watches. And it’s twice as accurate than Rolex Chronometer Superlative.

This is how the Grand Seiko Spring Drive works.

Grand Seiko says the Spring Drive works like so:

The battery sends electricity to a quartz oscillator, whose precise vibrations are detected by an integrated circuit (IC). The IC then moves the gears forward by exactly one second. The precision control of the IC allows for a high standard of accuracy, with Grand Seiko quartz models achieving a yearly rate of ±10 seconds.

The integrated circuit handles dividing the crystal’s high pule without using the battery, triggering a stepper motor to pump out single-second increments that allow the second hand to move. The integrated circuit is what regulates driving the gears. It observes the speed of the driving force behind the glide wheel and compares it to the oscillator. If the glide wheel is rotating too fast for the oscillator, it applies a magnetic brake.

The Grand Seiko Spring Drive is powered by a mainspring.

Like all other mechanical watches, the Spring Drive is powered by a traditional mainspring. Energy is stored by winding the mainspring by either turning the crown or moving the wrist. The energy is then transferred to the gears and used to move the hands of the watch.

Grand Seiko watches takes full advantage of the high level of torque gained by the mainspring so that it does not need another power source to move the hands of the watch that glide so smoothly.

This isn’t the first time Seiko used quartz movement to increase power and precision in a watch. Seiko was the first watchmaker to put quartz movement in professional dive watches—the Seiko Prospex Watches. Innovation is what Seiko does best.